Bottom Line:
The failed cases in terms of image uniformity and the CT number of water decreased in 2006.In 2006, the proportion of CT scanners manufactured before 1995 decreased (from 12.9% to 9.3%).The continued progress in the CT accreditation program may achieve improved image quality and thereby improve the national health of Korea.

Affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Korea.

ABSTRACT

Objective: The CT accreditation program was established in 2004 by the Korean Institute for Accreditation of Medical Image (KIAMI) to confirm that there was proper quality assurance of computed tomography (CT) images. We reviewed all the failed CT phantom image evaluations performed in 2005 and 2006.

Materials and methods: We analyzed 604 failed CT phantom image evaluations according to the type of evaluation, the size of the medical institution, the parameters of the phantom image testing and the manufacturing date of the CT scanners.

Results: The failure rates were 10.5% and 21.6% in 2005 and 2006, respectively. Spatial resolution was the most frequently failed parameter for the CT phantom image evaluations in both years (50.5% and 49%, respectively). The proportion of cases with artifacts increased in 2006 (from 4.5% to 37.8%). The failed cases in terms of image uniformity and the CT number of water decreased in 2006. The failure rate in general hospitals was lower than at other sites. In 2006, the proportion of CT scanners manufactured before 1995 decreased (from 12.9% to 9.3%).

Conclusion: The continued progress in the CT accreditation program may achieve improved image quality and thereby improve the national health of Korea.

Figure 3: Failure rates for various sized medical institutions in 2005 and 2006. General hospitals showed lower total failure rate than hospitals or clinics in 2005 and 2006. Generally, in 2006 total failure rate doubled relative to 2005; however, failure rate at general hospitals did not increase at same level. Therefore, most of increase of failed cases occurred in hospitals and clinics.

Mentions:
In 2005, the test was performed on 413 CT scanners in general hospitals, on 551 CT scanners in hospitals and on 583 CT scanners in clinics. The number of failed cases was 24, 74 and 81, respectively, for each type of institution. Among the 179 failed cases, the distribution for each institution type was 13.4% (24/179), 41.3% (74/179) and 45.3% (81/179), respectively, and the failure rate, according to the type of medical institution, was 5.8% (24/413), 13.4% (74/551) and 13.9% (81/583), respectively. In 2006, the test was performed on 446 CT scanners in general hospitals, on 552 CT scanners in hospitals and on 588 CT scanners in clinics; the number of failed cases was 35, 200 and 190, respectively. Among the 425 failed cases, the respective distribution was 8.2% (35/425), 47.1% (200/425) and 44.7% (190/425), respectively, and the failure rate, according to the type of the medical institution, was 7.8% (35/446), 36.2% (200/552), and 32.3% (190/588), respectively (Table 4). General hospitals had a lower failure rate than the hospitals or clinics in 2005 and 2006 (p = 0.000). The hospitals and clinics showed no remarkable difference in failure rate both in 2005 (p = 0.820) and 2006 (p = 0.164). In 2006, the total failure rate doubled (from 10.5% to 21.6%); however, the failure rate of general hospitals did not significantly increased in 2006 (p = 0.239). Therefore, the increase in failed cases was largely attributed to the increased failure rates of hospitals or clinics (Fig. 3).

Figure 3: Failure rates for various sized medical institutions in 2005 and 2006. General hospitals showed lower total failure rate than hospitals or clinics in 2005 and 2006. Generally, in 2006 total failure rate doubled relative to 2005; however, failure rate at general hospitals did not increase at same level. Therefore, most of increase of failed cases occurred in hospitals and clinics.

Mentions:
In 2005, the test was performed on 413 CT scanners in general hospitals, on 551 CT scanners in hospitals and on 583 CT scanners in clinics. The number of failed cases was 24, 74 and 81, respectively, for each type of institution. Among the 179 failed cases, the distribution for each institution type was 13.4% (24/179), 41.3% (74/179) and 45.3% (81/179), respectively, and the failure rate, according to the type of medical institution, was 5.8% (24/413), 13.4% (74/551) and 13.9% (81/583), respectively. In 2006, the test was performed on 446 CT scanners in general hospitals, on 552 CT scanners in hospitals and on 588 CT scanners in clinics; the number of failed cases was 35, 200 and 190, respectively. Among the 425 failed cases, the respective distribution was 8.2% (35/425), 47.1% (200/425) and 44.7% (190/425), respectively, and the failure rate, according to the type of the medical institution, was 7.8% (35/446), 36.2% (200/552), and 32.3% (190/588), respectively (Table 4). General hospitals had a lower failure rate than the hospitals or clinics in 2005 and 2006 (p = 0.000). The hospitals and clinics showed no remarkable difference in failure rate both in 2005 (p = 0.820) and 2006 (p = 0.164). In 2006, the total failure rate doubled (from 10.5% to 21.6%); however, the failure rate of general hospitals did not significantly increased in 2006 (p = 0.239). Therefore, the increase in failed cases was largely attributed to the increased failure rates of hospitals or clinics (Fig. 3).

Bottom Line:
The failed cases in terms of image uniformity and the CT number of water decreased in 2006.In 2006, the proportion of CT scanners manufactured before 1995 decreased (from 12.9% to 9.3%).The continued progress in the CT accreditation program may achieve improved image quality and thereby improve the national health of Korea.

Affiliation:
Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Korea.

ABSTRACT

Objective: The CT accreditation program was established in 2004 by the Korean Institute for Accreditation of Medical Image (KIAMI) to confirm that there was proper quality assurance of computed tomography (CT) images. We reviewed all the failed CT phantom image evaluations performed in 2005 and 2006.

Materials and methods: We analyzed 604 failed CT phantom image evaluations according to the type of evaluation, the size of the medical institution, the parameters of the phantom image testing and the manufacturing date of the CT scanners.

Results: The failure rates were 10.5% and 21.6% in 2005 and 2006, respectively. Spatial resolution was the most frequently failed parameter for the CT phantom image evaluations in both years (50.5% and 49%, respectively). The proportion of cases with artifacts increased in 2006 (from 4.5% to 37.8%). The failed cases in terms of image uniformity and the CT number of water decreased in 2006. The failure rate in general hospitals was lower than at other sites. In 2006, the proportion of CT scanners manufactured before 1995 decreased (from 12.9% to 9.3%).

Conclusion: The continued progress in the CT accreditation program may achieve improved image quality and thereby improve the national health of Korea.